The spread of bacterial infection in connection with cow teats during the milking process results in the spread of the infectious mammary disease known as mastitis. Bovine mastitis is an inflammation of the udder. The characteristic features of inflammation are swelling, heat, redness, pain, and disturbed function. This condition, which is almost exclusively initiated by pathogenic microorganisms that have entered the teat canal after the milking process, occludes milk flow and production, decreases milk value, and may permanently impair an animal's ability to produce milk. More than 80 species of microorganisms have been identified as causal agents, although approximately 95% of mastitis is believed to be caused by four pathogens: staphylococcus aureus, streptococcus agalactiae, streptococcus dysagalactiae, and streptococcus uberis. Mastitis-causing pathogens fall into two categories, namely, contagious and environmental. Contagious bacteria, such as streptococcus agalactiae and staphylococcus aureus, primarily colonize host tissue sites such as mammary glands, teat canals, and teat skin lesions; and are spread from one infected cow to another during the milking process. Environmental bacteria, often streptococci, enterococci, and coliform organisms, are commonly present within the cow's surroundings from sources such as cow feces, soil, plant material, bedding, or water; and infect by casual opportunistic contact with an animal.
The distinction between contagious and environmental pathogens, although not exclusive, is of practical importance because different dairy herd maintenance measures are needed for the different groups of microorganisms. In all bovine mastitis cases, whatever the causal microorganism, the route of transmission of the invading pathogen into the inner gland of the udder is through the teat orifice and teat canal. The common sources of harmful microorganisms include unsanitary milking equipment, the milker, other mastitic animals, an unsanitary stable environment, and the animals' own elimination (defecation/urination) processes.
A 1996 study by the National Mastitis Council (NMC) estimated annual monetary losses per cow due to mastitis at $184.40 totaling to an extrapolated average of $1.7 billion in the U.S. alone (Crist, W. L. et al., (1997) Mastitis and Its Control, University of Kentucky Extension Service—College of Agriculture). The spread of this disease is generally reduced by the use of antimicrobial compositions; for example, antimicrobial teat dips containing iodine have been shown to be effective against mammary infections and mastitis-causing bacteria (Pankey, J. W. et al., (1983) J. Dairy Sci. 66 (1), 161–167). These compositions are usually administered to the teat by dipping or spraying the teat prior to milking as well as after removal of the milking cup. To reduce mastitis, commercial teat dips have been developed containing a variety of antimicrobial agents including iodophors, quaternary ammonium compounds, chlorine release compounds (e.g. alkali hypochlorites), oxidizing compounds (e.g. hydrogen peroxide, peracids), protonated carboxylic acids (e.g. heptanoic, octanoic, nonanoic, decanoic, undecanoic acids), acid anionics (e.g. alkylaryl sulfonic acids), chlorine dioxide (from chlorite), and bisbiguanides such as chlorhexidine. These agents, which have varying degrees of effectiveness, limit the transmission of mastitis by reducing pathogen populations on the teat. However, there are problems associated with the use of antimicrobials. The most prevalent are irritation to the teat and teat cracking. To alleviate these problems, emollient additives such as glycerin and lanolin have been included in such compositions. However, even with the use of these emollients skin irritation can still occur.
The NMC not only stresses the importance of proper teat sanitation, but also proper teat care for the prevention of mastitis. The economic harm caused by mastitis has led to much research in its control. Physical stresses as well as environmental conditions have been reported to be large contributors to mastitis infection (See U.S. Patent: 20020051789). Since it was documented that sub-clinical mastitis was directly related to poor teat condition (Neijenhuis, P. et al., (2001) J. Dairy Sci. (84) 2664–2672), a number of commercial teat dip solutions incorporating conditioning agents have evolved (National Mastitis Council, Summary of Peer-Reviewed Publications on Efficacy of Premilking and Postmilking Teat Disinfectants Published Since 1980; January 2002). Recently, teat end callosity and roughness have been shown to have a direct relationship with clinical mastitis (Neijenhuis, F. et al., (2001) J. Dairy Sci. (84) 2664–2672). The reduction of chapping and irritation of teats as well as keeping the teat flexible is very important in controlling mammary infections. Currently, glycerin is often used as a teat conditioner in teat dip solutions. However, studies indicate no significant decrease in mastitis-causing bacteria such as staphylococcus aureus, streptococcus agalactiae, or coliforms when the glycerin content is increased from 2% to 10% in a 1% iodine teat dip solution (National Mastitis Council, Summary of Peer-Reviewed Publications on Efficacy of Premilking and Postmilking Teat Disinfectants Published Since 1980; January 2002).
Thus, although many teat dip products are available, there is a continuing need for new and effective teat dip compositions having immediate and long lasting antimicrobial effect against a wide spectrum of mastitis-causing organisms that also aid in overall skin condition of the teat.